It is a known fact that difunctional ester compounds, acid halides, and alcohol compounds are useful as monomer components for preparing condensation polymers. Much attention has been recently focused on the characteristics of fluorine compounds, such as chemical resistance, weather fastness, water/oil repellency, less intermolecular interaction, low refractive index, and high light transmittance, and thus development of fluorine-containing polymers has been enthusiastically promoted.
For instance, examples of polycondensation type fluorine-containing polymers for optical waveguide are described in WO03/099907A1 and the references cited therein. It is also described in WO03/037838 A1, JP-A-5-70522 (“JP-A” means unexamined published Japanese patent application), and the references cited therein that polymers obtained by cyclization polymerization of fluorine-containing m-alkenyl vinyl ethers are useful for optical materials such as optical fibers. In addition, it is known that homopolymers of a perfluorodioxol compound as described in U.S. Pat. Nos. 3,978,030 and 4,399,264 and copolymers of this perfluorodioxol compound and tetrafluoroethylene or the like form amorphous polymers, and these can be used in the same applications.
On the other hand, fluorine-containing difunctional compounds and producing methods thereof are described, for example, in WO02/004397.
However, none of the above references describes the fluorine-containing spiroacetal compound of the present invention and producing methods thereof.